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  <div class="section" id="numpy-unpackbits">
<h1>numpy.unpackbits<a class="headerlink" href="#numpy-unpackbits" title="Permalink to this headline">¶</a></h1>
<dl class="function">
<dt id="numpy.unpackbits">
<code class="sig-prename descclassname">numpy.</code><code class="sig-name descname">unpackbits</code><span class="sig-paren">(</span><em class="sig-param">a</em>, <em class="sig-param">axis=None</em>, <em class="sig-param">count=None</em>, <em class="sig-param">bitorder='big'</em><span class="sig-paren">)</span><a class="headerlink" href="#numpy.unpackbits" title="Permalink to this definition">¶</a></dt>
<dd><p>Unpacks elements of a uint8 array into a binary-valued output array.</p>
<p>Each element of <em class="xref py py-obj">a</em> represents a bit-field that should be unpacked
into a binary-valued output array. The shape of the output array is
either 1-D (if <em class="xref py py-obj">axis</em> is <code class="docutils literal notranslate"><span class="pre">None</span></code>) or the same shape as the input
array with unpacking done along the axis specified.</p>
<dl class="field-list">
<dt class="field-odd">Parameters</dt>
<dd class="field-odd"><dl>
<dt><strong>a</strong><span class="classifier">ndarray, uint8 type</span></dt><dd><p>Input array.</p>
</dd>
<dt><strong>axis</strong><span class="classifier">int, optional</span></dt><dd><p>The dimension over which bit-unpacking is done.
<code class="docutils literal notranslate"><span class="pre">None</span></code> implies unpacking the flattened array.</p>
</dd>
<dt><strong>count</strong><span class="classifier">int or None, optional</span></dt><dd><p>The number of elements to unpack along <em class="xref py py-obj">axis</em>, provided as a way
of undoing the effect of packing a size that is not a multiple
of eight. A non-negative number means to only unpack <em class="xref py py-obj">count</em>
bits. A negative number means to trim off that many bits from
the end. <code class="docutils literal notranslate"><span class="pre">None</span></code> means to unpack the entire array (the
default). Counts larger than the available number of bits will
add zero padding to the output. Negative counts must not
exceed the available number of bits.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 1.17.0.</span></p>
</div>
</dd>
<dt><strong>bitorder</strong><span class="classifier">{‘big’, ‘little’}, optional</span></dt><dd><p>The order of the returned bits. ‘big’ will mimic bin(val),
<code class="docutils literal notranslate"><span class="pre">3</span> <span class="pre">=</span> <span class="pre">0b00000011</span> <span class="pre">=&gt;</span> <span class="pre">[0,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">1,</span> <span class="pre">1]</span></code>, ‘little’ will reverse
the order to <code class="docutils literal notranslate"><span class="pre">[1,</span> <span class="pre">1,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">0,</span> <span class="pre">0]</span></code>.
Defaults to ‘big’.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 1.17.0.</span></p>
</div>
</dd>
</dl>
</dd>
<dt class="field-even">Returns</dt>
<dd class="field-even"><dl class="simple">
<dt><strong>unpacked</strong><span class="classifier">ndarray, uint8 type</span></dt><dd><p>The elements are binary-valued (0 or 1).</p>
</dd>
</dl>
</dd>
</dl>
<div class="admonition seealso">
<p class="admonition-title">See also</p>
<dl class="simple">
<dt><a class="reference internal" href="numpy.packbits.html#numpy.packbits" title="numpy.packbits"><code class="xref py py-obj docutils literal notranslate"><span class="pre">packbits</span></code></a></dt><dd><p>Packs the elements of a binary-valued array into bits in a uint8 array.</p>
</dd>
</dl>
</div>
<p class="rubric">Examples</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">a</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">array</span><span class="p">([[</span><span class="mi">2</span><span class="p">],</span> <span class="p">[</span><span class="mi">7</span><span class="p">],</span> <span class="p">[</span><span class="mi">23</span><span class="p">]],</span> <span class="n">dtype</span><span class="o">=</span><span class="n">np</span><span class="o">.</span><span class="n">uint8</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">a</span>
<span class="go">array([[ 2],</span>
<span class="go">       [ 7],</span>
<span class="go">       [23]], dtype=uint8)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">b</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">unpackbits</span><span class="p">(</span><span class="n">a</span><span class="p">,</span> <span class="n">axis</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">b</span>
<span class="go">array([[0, 0, 0, 0, 0, 0, 1, 0],</span>
<span class="go">       [0, 0, 0, 0, 0, 1, 1, 1],</span>
<span class="go">       [0, 0, 0, 1, 0, 1, 1, 1]], dtype=uint8)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">c</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">unpackbits</span><span class="p">(</span><span class="n">a</span><span class="p">,</span> <span class="n">axis</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">count</span><span class="o">=-</span><span class="mi">3</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">c</span>
<span class="go">array([[0, 0, 0, 0, 0],</span>
<span class="go">       [0, 0, 0, 0, 0],</span>
<span class="go">       [0, 0, 0, 1, 0]], dtype=uint8)</span>
</pre></div>
</div>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">p</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">packbits</span><span class="p">(</span><span class="n">b</span><span class="p">,</span> <span class="n">axis</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">unpackbits</span><span class="p">(</span><span class="n">p</span><span class="p">,</span> <span class="n">axis</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="go">array([[0, 0, 0, 0, 0, 0, 1, 0],</span>
<span class="go">       [0, 0, 0, 0, 0, 1, 1, 1],</span>
<span class="go">       [0, 0, 0, 1, 0, 1, 1, 1],</span>
<span class="go">       [0, 0, 0, 0, 0, 0, 0, 0],</span>
<span class="go">       [0, 0, 0, 0, 0, 0, 0, 0],</span>
<span class="go">       [0, 0, 0, 0, 0, 0, 0, 0],</span>
<span class="go">       [0, 0, 0, 0, 0, 0, 0, 0],</span>
<span class="go">       [0, 0, 0, 0, 0, 0, 0, 0]], dtype=uint8)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">array_equal</span><span class="p">(</span><span class="n">b</span><span class="p">,</span> <span class="n">np</span><span class="o">.</span><span class="n">unpackbits</span><span class="p">(</span><span class="n">p</span><span class="p">,</span> <span class="n">axis</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">count</span><span class="o">=</span><span class="n">b</span><span class="o">.</span><span class="n">shape</span><span class="p">[</span><span class="mi">0</span><span class="p">]))</span>
<span class="go">True</span>
</pre></div>
</div>
</dd></dl>

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